Water-soluble polyvinylpyrrolidone nanofilters manufactured by electrospray-neutralization technique

This report describes the mechanical and electrical properties, resistance to airflow, and capturing efficiency of water-soluble nanofilters to be used in the collection of biological micro- and nano-aerosols for analysis of biohazards. The filters were manufactured from polyvinylpyrrolidone (PVP) solutions using the recently developed modified technology of electrospinning, employing gas-phase neutralization of electrospun nanofibers with a cloud of small counter-ions generated by electrospraying a volatile solvent. Aerosol penetration and resistance to airflow were characterized as a function of filter thickness, reinforcement by a mesh support, and relative air humidity. In a series of nanofilters of different thicknesses, it was established that while resistance to airflow grows proportionally to filter thickness, the penetration of aerosol particles decreases exponentially. It was shown that PVP nanofilters can be stored for months and retain filtration properties at air humidity below 75%.